The market for displays and other devices (e.g., keyboards) having touch functionality is rapidly growing. As a result, touch-sensing techniques using touch screens have been developed to enable displays and other devices to have touch functionality. Touch-sensing functionality is gaining wider use in mobile device applications, such as smart phones, e-book readers, laptop computers and tablet computers.
Touch systems having touch screens have been developed so that they respond to a variety of types of touches, such as single touches, multiple touches, swiping, and touches having different pressures. Unfortunately, present-day pressure sensing capability of touch screens is limited by sensor performance. Further, more accurate determination of the touching forces associated with multiple touches is needed to improve the touch-sensing capability of touch screens.